Isolated Isomers of Norelgestromin and Methods of Making and Using the Same

ABSTRACT

The invention is directed to a process of preparing substantially pure d-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-3E- and -3Z-oxime isomers, as well as a process for the synthesis of the mixture of isomers and the pure isomers. The invention also relates to substantially pure d-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene20-yn-3-one-3E-oxime and substantially pure d-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-3Z-oxime isomer. Further aspects of the invention include a composition comprising substantially pure d-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene20-yn-3-one-3E-oxime or substantially pure d-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-3Z-oxime isomer, and methods of treatment using said compositions.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Application Ser. No.10/879,710. Priority under 35 U.S.C. §119(a)-(d) is hereby claimed toHungarian patent application No. P 03 01981, filed Jun. 30, 2003, and toHungarian patent application No. P 03 01982, filed Jun. 30, 2003, bothof which are incorporated by reference in their entireties.

BACKGROUND OF THE INVENTION

The present invention relates to a process for producing norelgestromin,including the oxime isomers thereof, and suitable compositionscomprising norelgestromin. The invention is also directed to methods oftreatment comprising administering norelgestromin.

BACKGROUND ART

The synthesis and biological investigation of 3-oximino-androstene- andgonene derivatives containing a sterane skeleton started in the 1960s.The application ofdl-(17α)-13-ethyl-17-(acetyloxy)-18,19-dinorpregn-4-ene-20-yn-3-one-oximederivatives as postcoital contraceptives is suggested in U.S. Pat. No.3,780,073.

The synthesis of dl- andd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-oxime isdescribed in Hungarian Patent No. 165,356. The compounds are describedas the intermediates of the synthesis of the racemic and opticallyactive norgestrel, but their biological activity is not given.

The synthesis ofd-(17α)-13-ethyl-17-(acetyloxy)-18,19-dinorpregn-4-ene-20-yn-3-one-oxime(norgestimate) is described in the U.S. Pat. No. 4,027,019.

The biological and clinical investigation of norgestimate demonstratedadvantageous inhibition of fertility. Norgestimate in combination withethinyl estradiol gained therapeutic application as ORTHO-CYCLEN® andCILEST. The use of the optically active isomer of norgestimate madepossible the application of the active ingredient in lower dosage thanin the case of the racemic mixture

Progress occurred with the synthesis of 17-deacetylnorgestimate(norelgestromin) and the pharmacological as well as clinicalinvestigation thereof. The following publications, Am. J. Obstet.Gynecol., 166, 1969-77 (1992) and Am. J. Obstet. Gynecol, 163:2127-31(1990), disclose that the metabolites of orally applied norgestimate are17-deacetylnorgestimate and 3-keto-norgestimate (d-norgestrel acetate),as well as d-norgestrel (levonorgestrel), which have significantbiological activity.

U.S. Pat. No. 4,906,169 describes the use of norgestimate andd-norgestrel in combination with an estrogen component in transdermalpatch.

Published PCT application WO 96/40355 discloses the use ofdeacetylnorgestimate, one of the metabolites of norgestimate, alone orin combination with an estrogen component in a transdermal patch.

BRIEF SUMMARY OF THE INVENTION

It is generally desirable to decrease the dose of active ingredientsused in the therapy. This is especially true for steroid derivativespossessing high biological activity. The aim of our research was tosynthesize and investigate the biological effect of the pure opticalantipodes of steroid derivatives, which had been described in theliterature earlier as racemic mixtures.

The invention relates to a process of preparing substantially pured-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-3E-oximeof Formula I

The invention also relates to a process of preparing substantially pured-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-3Z-oximeof Formula II

The invention also relates to the process for the synthesis of themixture of the above isomers and of the pure isomers. The invention alsorelates to compositions (such as pharmaceutical compositions) comprisinga substantially pure oxime of Formula I or II. In another embodiment,the present invention is directed to an isolated, substantially purecompound of Formula I. In another embodiment, the invention is directedto an isolated, substantially pure compound of Formula II. The isolatedcompounds are preferably suitable for use in a pharmaceuticalcomposition. In other embodiments, the composition of the presentinvention further comprises other active ingredients (for example, anestrogen agent) together with pharmaceutical auxiliary materialscommonly used in practice and as described herein. In yet otherembodiments, the present invention is directed to methods of treatmentcomprising administering compounds and compositions of the presentinvention. The compositions of the present invention are useful fortreating a number of conditions, including hormone replacement therapy.Furthermore, the compounds and compositions are useful in thepreparation of and use as contraceptive agents. Another aspect of theinvention is a process of synthesizing norelgestromin and the oximeisomers thereof on an industrial scale.

It is believed that the method of the present invention differs fromprior art methods of preparing compounds of Formula I or II. In certainembodiments, the present invention prepares a compound of Formula I orII having a higher purity with respect to the oxime isomer.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

FIG. 1 shows the correlation between measured and predicted logkp data(95% confidence intervals are indicated by dashed lines) for sixsteroid-type compounds.

DETAILED DESCRIPTION OF THE INVENTION

The separation of several known steroids, among them norelgestromin, byhigh pressure chromatography is described in: J. Chromatogr., 392:464-9(1987), but only the chromatographical parameters and not thephysicochemical properties of the separated oxime isomers, which provethe structures, are given. Furthermore, the isomers in isolated,substantially pure form are not described.

The examination of some intermediate of the synthesis of norgestrel byhigh performance liquid chromatography (HPLC) and gas-liquidchromatography (GLC) is described in J. Chrornatogr. 191(1):145-54.(1980). Among the above compounds are the racemic mixture and theoptically pure oxime derivatives as well, which are disclosed in theHungarian Patent No. 165,356. From the description, it is ambiguouswhether the optically pure or the racemic mixture of steroid oximederivatives were examined. According to the above publication, the oximeisomers were separated by normal phase analytical HPLC, and theirstructures were elucidated. For the structure elucidation, they refer tothe publication of Hara and coworkers (Chem. Ind. (London), 832 (1967)),where the syn and anti oxime isomers of testosterone were separated.Their structures were examined by NMR and UV spectroscopical methods.The significant difference measured in the molar absorption of the twooxime isomers at 242 nm wavelength was emphasized.

A general goal of the pharmaceutical industry is the synthesis ofstructurally homogeneous and stereochemically pure active ingredients(i.e., single enantiomer and diastereomer), and their use in therapy,which may lead to the application of a lower dose of the activeingredients having unambiguous biological activity profile and thereforedecreased side effects.

As described above, the known procedures for the synthesis of steroidcompounds containing an oxime group at position 3, e.g., norgestimateand 17-deacetylnorgestimate, lead to an isomeric mixture of oximes,where the ratio of isomers is about 60:40 to about 64:36 E/Z-oximes.

Surprisingly, it was found by the present inventors that using theprocess according to invention described herein for the oximationreaction, and for the work-up procedure of the obtained mixture ofoximes, either thed-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oximeord-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oxime,as well as the mixture of 3E- and 3Z-oximes, can be synthesized andprepared as required.

In one embodiment, the invention relates to a process of preparingsubstantially pured-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-3E-oximeisomer of Formula I

In another embodiment, the invention also relates to a process ofpreparing substantially pured-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-3Z-oximeisomer of Formula II

In addition, the invention relates to a process for the synthesis of themixture of the above isomers and of the pure isomers. The invention alsorelates to compositions (such as pharmaceutical compositions) comprisinga substantially pure oxime of Formulas I or II. In one embodiment, thepresent invention is directed to an isolated, substantially purecompound of Formula I. In another embodiment, the invention is directedto an isolated, substantially pure compound of Formula II. The isolatedcompounds are preferably suitable for use in a pharmaceuticalcomposition. In other embodiments, the composition of the presentinvention further comprises other active ingredients (for example, anestrogen agent) together with pharmaceutical auxiliary materialscommonly used in practice and as described herein.

In yet other embodiments, the present invention is directed to methodsof treatment comprising administering compounds and compositions of thepresent invention. The compositions of the present invention are usefulfor treating a number of conditions, including hormone replacementtherapy. Furthermore, the compounds and compositions are useful in thepreparation of and use as contraceptive agents.

D-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-oxime isused in therapy as a stereochemical mixture of isomers of E/Z oximes.The use of a single substantially pure isomer makes possible a number ofadvantages, including an increase in the homogeneity of the biologicalactivity profile of a pharmaceutical composition comprising the isomer.Furthermore, the use of a substantially pure isomer allows one to takeadvantage of the different physical properties (for example solubility,permeability, absorption) of the individual isomer in realization of amore suitable application method in therapy.

Synthesis

In one embodiment, the process of preparingd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oximecomprises converting d-norgestrel into a mixture of norelgestromin oximeisomers; adding about 10 to about 25 volume percent of water to thereaction mixture comprising the norelgestromin isomers; and stirring theresulting mixture for at least about 24 hours. The process optionallycomprises additional steps, such as adding additional water after thestirring period to precipitate the E-norelgestromin, and optionallyfurther purifying the E-norelgestromin obtained from the process.

The d-norgestrel can be converted into norelgestromin under a variety ofoximation conditions. For example, hydroxylammonium acetate or ahydroxylammonium salt can be used to convert d-norgestrel tonorelgestromin. A suitable hydroxylammonium salt includeshydroxylammonium chloride. In certain embodiments, when ahydroxylammonium salt is used, a base is also use, such as for exampleacetate, pyridine, and the like. Of course, other procedures for formingthe oxime group on norelgestromin are understood to be encompassed bythe present invention. For example, any of the processes of oximationdescribed in copending application Ser. No. 10/879,708 (Attorney DocketNo. 2124.0040000) titled “Process for the synthesis of high purity d(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-oxime,”filed Jun. 30, 2004, which is incoporated herein by reference in itsentirety, can be used.

Additionally, any solvent or mixtures of solvents that allow thereaction to proceed as described can be used in each of the steps of thepresent invention. Both organic and inorganic solvents are known in theart. Such solvents include chloroform, dichloromethane, methanol,ethanol, ethyl acetate, acetone, benzene, toluene, carbon tetrachloride,acetic acid, tetrahydrofuran, and the like.

The precise temperature at which the reaction mixture is stirred, afteraddition of the water, can vary. In certain embodiments, the reactionmixture is stirred at a temperature of about 10° C. to about 30° C. Inanother embodiment, the reaction mixture is stirred at a temperature ofabout 0° C. to about 45° C. Generally, stirring at room temperature issuitable.

The resulting E-norelgestromin can be isolated using standardprocedures, such as adding water to the reaction mixture, and isolatingthe precipitated product. Optionally, the E-norelgestromin is furtherpurified by recrystallization in a suitable solvent.

In other embodiments, the step of converting d-norgestrel tonorelgestromin is performed under an inert atmosphere. A suitable inertatmosphere includes but is not limited to nitrogen and argon. In certainembodiments, the inert atmosphere is a dry atmosphere having a lowmoisture content. Such inert atmospheres are understood in the art.

By way of example, the process according to this embodiment comprisesconverting d-norgestrel into a mixture of norelgestromin isomers; andadding to the reaction mixture about 10 to about 25 volume percent ofwater; and stirring the resulting mixture for at least 24 hours. Inother embodiments, said d-norgestrel is reacted with hydroxylammoniumacetate in a ratio of about 1.2 mol to about 5 mol per mole of saidd-norgestrel, in acetic acid containing not more than 50 mass percent ofwater; at a temperature of about 15° C. to about 50° C.; and stirred forabout 15 minutes to about 45 minutes. In another embodiment, saidreaction mixture is stirred for about 24 to about 72 hours after theaddition of water.

In another embodiment, the d-norgestrel is reacted with ahydroxylammonium salt in a ratio of about 1.2 to about 5 mol per mole ofd-norgestrel, and with an alkali metal acetate in a ratio of not morethan 1 mole per mole of said hydroxylammonium salt; in acetic acidcontaining not more than 50 mass percent of water; at a temperature ofabout 15° C. to about 50° C.; and stirred for about 15 minutes to about45 minutes.

In another embodiment of the invention, hydroxylammonium hydrochlorideand sodium acetate are suspended in glacial acetic acid. The suspensionis stirred, for example, for 1 hour, and the formed sodium chloride isfiltered. Under nitrogen, d-norgestrel is added to the stirred solution,and stirring is continued until the reaction is complete. Then water isadded to the reaction mixture, and stirring is continued for about 20 toabout 100 hours, for example, for about 50 hours. The reaction mixtureis poured into water. The precipitated product is isolated and washed,and then dried. The E-norelgestromin is then optionally recrystallizedfrom a suitable solvent. Suitable solvents include, but are notnecessarily limited to, acetonitrile and ethyl acetate.

Other suitable ratios of hydroxylammonium chloride to norgestrel includeabout 2:1, about 3:1, and about 4:1.

In another embodiment, the process of preparingd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oximecomprises converting d-norgestrel into a mixture of norelgestromin oximeisomers; and after addition of about 10-fold volume of water, theprecipitated isomeric mixture is isolated and stirred indichloromethane. For example, in one embodiment the process of preparingd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oximecomprises a method as described above; and, after addition of about10-fold volume of water, the precipitated isomeric mixture is isolatedand stirred in dichloromethane. The insoluble (3E)-oxime isomer ofFormula I is filtered from the dichloromethane solution. The filtrate ispurified, for example, by column chromatography, to give the (3Z)-oximeof Formula II. For example, the Z-norelegestromin can be purified bycolumn chromatography using silica gel as adsorbent and a mixture ofapolar-polar solvents as eluent. Optionally, the Z-norelgestromin isfurther purified by recrystallization in a suitable solvent.

The preceding embodiment is also suitable for the preparation ofd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oxime.In this case, the insoluble (3E)-oxime isomer of Formula I is filteredfrom the dichloromethane solution. In one embodiment, theE-norelgestromin is obtained having a isomeric purity of at least 90%,preferably at least 94%. The E-oxime isomer so obtained can then befurther purified, for example, by recrystallization.

By way of example, an embodiment of the invention comprises thefollowing process. A suspension of sodium acetate, hydroxylammoniumhydrochloride, and aqueous acetic acid is vigorously stirred, forexample at room temperature for about 1 hour. The precipitated sodiumchloride is filtered. D-norgestrel is added to the solution under aninert atmosphere, for example under nitrogen or argon, and the resultingmixture is stirred for about 0.5 hours to about 5 hours. Other suitabletimes include about 1, about 1.5, and about 2 hours. During this time,the temperature of the reaction is allowed to rise to about 45° C. Whenthe reaction is complete, the reaction mixture is poured into water. Theprecipitated product is isolated and dried using standard techniques.For example, the isolated product is filtered, washed successively withwater, 5% aqueous ammonium hydroxide solution, and then water untilneutral, and then dried. The isolated product is a mixture of oximeisomers of norelgestromin, in certain embodiments having a ratio E:Z ofabout 60:40 to about 50:50. The mixture of isomers is then stirred indichloromethane. The volume of dichloromethane may vary. Suitablevolumes include 18-fold, 20-fold, and 22-fold volume. The time ofstirring may vary as well. In one embodiment, the mixture is stirred forabout 30 minutes. Other suitable times include but are not limited to10, 20, 40, 50 and 60 minutes. In this way, the Z-oxime isomer isrelatively soluble, whereas the E-oxime isomer of norelgestromin is lesssoluble and is filtered from the dichloromethane solution. The E-oximenorelgestromin obtained this way is in certain embodiments substantiallypure. The E-isomer can optionally be dried, preferably below 60° C.

The mother liquor obtained after isolating the E-oxime isomer is thenconcentrated to yield a mixture of isomers, (e.g., Z oxime about 65%,E-oxime about 33%). The residue obtained is dissolved in dichloromethaneand kept at a cooled temperature, for example about 0° C. to about 5° C.After some time, for example about 2 to about 8 hours, the precipitatedcrystalline product is filtered off, washed with dichloromethane, anddried to yield substantially pure Z-norelgestromin.

Additional substantially pure E-norelgestromin and substantially pureZ-norelgestromin may be obtained from the dichloromethane mother liquorby column chromotagraphy.

The substantially pure E-norelgestromin and substantially pureZ-norelgestromin is optionally further purified by recrystallization toincrease the purity, e.g., to obtain an isomeric purity of greater than99%.

In another embodiment, the present invention is directed to a process ofpreparing d-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oximecomprising stirring a mixture of E and Z isomers of norelgestromin ofany ratio with either hydroxylammonium acetate or with ahydroxylammonium salt and up to one equivalent of the alkali metalacetate per hydroxylammonium salt, in acetic acid containing not morethan 50 mass percent of water; at about 15° C. to about 30° C. for about24 to about 72 hours. The E-norelgestromin may be isolated usingstandard techniques, for example, addition of additional water toisolate. Optionally, the process further comprises purifying theobtained E-norelgestromin by, for example, recrystallization, columnchromatography, or flash chromatography.

The substantially pure E-isomer can be produced from any E/Z isomericmixture. In another embodiment, the substantially pure Z-isomer ofnorelgestromin can be converted into the substantially pure E-isomer ofnorelgestromin according the described process.

For example, the reaction mixture is stirred for approximately 24 to 72hours, preferably for 48 hours, after consumption of the startingmaterial, without isolating the formed oxime, and carrying out thereaction under the above reaction conditions, using glacial acetic acidor 85% aqueous acetic acid as solvent, and the formed product isfiltered off or isolated after addition of water. Then the obtainedisomeric mixture contains the E/Z isomers of norelgestromin in a ratioof about 94:6.

In another embodiment, the present invention is directed to a process ofpreparingd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oximecomprising stirring a mixture of E/Z isomers of norelgestromin of anyratio in dichloromethane; filtering from the dichloromethane solutionthe insoluble (3E)-oxime isomer of Formula I; and purifying thefiltrate, for example by column chromatography, using silica gel asadsorbent and a mixture of apolar-polar solvents as eluent to give the(3Z)-oxime of Formula II. In a further embodiment, the chromatography isperformed using silica gel as adsorbent and a mixture of apolar-polarsolvents as eluent. The Z-norelgestromin can optionally be furtherpurified by recrystallization from a suitable solvent.

Any solvent or mixture of solvents that allows the separation of theisomers by column chromatography can be used. Such solvents include butare not necessarily limited to hexanes, acetone, toluene, chloroform,methanol, ethanol, isopranol, ethyl acetate, and the like. Any solventor mixture of solvents that allows recrystallization of the isomers canbe used. Such solvents include but are not necessarily limited toisopranol, methanol, ethanol, acetonitrile, etc.

In one respect, this process can be used to prepare each of the oximeisomers of norelgestromin. The E-norelgestromin is isolated as aprecipitate from the dicholormethane solution. The E-norelgestromin isthen further purified, for example, by recrystallization using assuitable solvent.

In another embodiment, norelgestromin is prepared by hydrolyzing theacetate group at position 17 of the 3E- or 3Z-isomer of norgestimate inalcoholic solution, e.g., methanol, ethanol, isopropanol, and butanol,with equivalent of metal hydroxide to have the obtained product, of thesame configuration as the starting material and isolating it to give the(3E)-oxime isomer of the Formula I or the (3Z)-oxime isomer of FormulaII. In another embodiment, the hydrolysis is carried out at atemperature of about 5 to about 30° C. In one embodiment of thisprocess, the hydrolysis is carried out on substantially pure3E-norgestimate or substantially pure 3Z-norgestimate. In this way, theprocess yields substantially pure 3E-norelgestromin or substantiallypure 3Z-norelgestromin, respectively. In a further embodiment, theprocess further comprises purifying the norelgestromin by, for example,recrystallization. Suitable metal hydroxides include alkali metalhydroxide and alkaline earth metal hydroxides. Suitable alkali metalhydroxides for the hydrolysis of norgestimate include but are notlimited to sodium hydroxide, and lithium hydroxide. Preferably, lithiumhydroxide monohydrate is used.

Various solvents can be used for the reaction. Such solvents includemethanol, ethanol, isopropanol, tetrahydrofuran, and the like andmixtures thereof. In a preferred embodiment, the the reaction is carriedout in methanol.

According to this embodiment, the substantially pure E- or Z-oximeisomers can be obtained from the knownd-(17α)-13-ethyl-17-(acetyloxy)-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-or -(3Z)-oxime by hydrolyzing the acetoxy group at position 17. Thestereochemical purity does not substantially change under the mildreaction conditions of hydrolysis according to the present invention. Inanother aspect, the E/Z isomeric mixture of norgestimate can separatedby a known chromatographical method (see for example J. Chromatogr.,635, 342-345 (1993)); the acetate group at position 17 of thesubstantially pure E- or Z-isomer oxime is then hydrolyzed according tothe present invention by a metal hydroxide, such as but not limited tolithium hydroxide or sodium hydroxide in alcoholic solution under mildconditions, preferably at about 5 to about 20° C. If the hydrolysis iscarried out under the conditions of the present invention, thestereochemistry of the hydroxyl group of the oxime group does notsubstantially change.D-(17α)-13-ethyl-17-(acetyloxy)-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-and -(3Z)-oximes are known in the art (see for example, J.Chromatography 635:342-345 (1993)).

In another embodiment, the present invention is directed to a process ofpreparing a mixture of oxime isomers of norelgestromin comprisingreacting d-norgestrel with about 1.2 to about 5 mol equivalents ofhydroxylammonium acetate; in acetic acid containing not more than 50mass percent of water; at about 15° C. to about 50° C.; for about 15minutes to about 45 minutes; and diluting with about a 10-fold volume ofwater to yield a precipitated isomeric mixture of E/Z norelgestrominisomers. In one embodiment, the E and Z isomers are produced in a ratioof about 56:44 to about 64:36.

In another embodiment, the present invention is directed to a process ofpreparing a mixture of oxime isomers of norelgestromin comprisingreacting d-norgestrel with 1.2 to about 5 mol equivalents of ahydroxylammonium salt along with not more than 1 mol equivalent (basedon the hydroxylammonium salt) of an alkali metal acetate; in acetic acidcontaining not more than 50 mass percent of water; at about 15° C. toabout 50° C.; for about 15 minutes to about 45 minutes; and dilutingwith about a 10-fold volume of water to yield a precipitated isomericmixture of E/Z norelgestromin isomers. In one embodiment, the E and Zisomers are produced in a ratio of about 56:44 to about 64:36.

Suitable hydroxylammonium salts include hydroxylammonium chloride andhydroxylamine nitrate, hydroxylamine phosphate, and hydroxylaminesulfate. Of course, other hydroxylammonium salts may be used in thepresent invention.

According to certain embodiments of the present invention, if theformation of oximes is carried out with hydroxylammonium hydrochlorideand sodium acetate, or with hydroxylammonium acetate in glacial aceticacid or in aqueous acetic acid, then the ratio of E/Z isomers in theobtained crude isomeric mixture can be varied between 56:44 and 94:6depending on the further treatment of the mixture. This allows forexample the isolation of E-oxime isomer directly from the reactionmixture, but also helps in isolating the Z-oxime isomer by columnchromatography, for example from the 56:44 mixture because this ratiocan be changed to a different ratio, for example about 65.5 to about34.5, after stirring in dichloromethane. The Z isomer can easily beisolated from this mixture, for example by column chromatography.

One embodiment of the process according to our invention can preferablybe carried out as follows. From about 1.2 to about 5 mol equivalent(calculated for 1 mol of d-norgestrel) of hydroxylammonium chloride andnot more than one equivalent of the latter of sodium acetate aresuspended in glacial acetic acid, and the obtained suspension (sodiumchloride precipitates) is stirred for 30 min. Then the sodium chlorideis filtered off. d-Norgestrel is added to the filtrate, and the reactionmixture is stirred until the reaction is complete (monitored by TLC).The reaction mixture is then diluted with water. The precipitatednorelgestromin is filtered off, washed with water, dried, andrecrystallized.

According to another embodiment of our invention, the sodium chloride isnot filtered off because, after addition of water, it dissolves and doesnot influence the yield and the quality of the product.

In certain embodiments, the E/Z ratio of the obtained mixture ofnorelgestromin oximes is about 60:40.

In other embodiments, hydroxylammonium acetate prepared in advance canalso be used as a suitable oximation reagent.

According to another embodiment of the invention, for example, a 60:40mixture of E/Z isomers or alternatively pure Z-isomer is suspended inacetic acid containing hydroxylammonium hydrochloride and not more thanone equivalent of the latter of sodium acetate and the above reactionconditions are applied. In this case, an isomeric mixture is obtainedcontaining the E/Z isomers in a ratio of about 90:10 to about 96:4.

In another embodiment, the oximation reaction is carried out by keepingthe reaction mixture homogeneous, and immediately after consumption ofthe starting material, the reaction mixture is diluted with water. Theprecipitated solid product is isolated, and then the isomeric ratio ofthe obtained mixture is 56:44 E/Z oximes. This isomeric mixture can thenbe stirred with dichloromethane as described above. In this instance,the less soluble E-isomer can be filtered off, and the isomeric ratio inthe filtrate can be enriched for the Z-isomer (about E/Z=33:77), whichassists in the isolation of Z-isomer by column chromatography.

In certain embodiments, the separation of E- and Z-isomers ofnorelgestromin is carried out by column chromatography using silica gelas adsorbent and starting the elution with a predominantly apolarmixture of solvents and gradually increasing the concentration of themore polar solvent. The fractions containing the same isomer areconcentrated and the residue is recrystallized.

According to the process of our invention, the pure E-oxime isomer canbe produced on industrial scale. The separation of Z-oxime isomer can beeconomical because the ratio of E/Z isomers can be varied for theZ-isomer oxime and from this mixture the Z-isomer can be isolated bycolumn chromatography. In another embodiment, the pure Z-oxime isomercan be produced on industrial scale.

In certain instances, the product of each step of the process isisolated and purified, for example by recrystallization. In otherinstances, the only final product of the E or Z norelgestromin isrecrystallized.

In another embodiment, the process according to our invention is thefollowing:

a) reacting d-norgestrel with 1.2-5 mol of hydroxylammonium acetate, orwith a hydroxylammonium salt in the presence of not more than one moleequivalent of alkali metal acetate calculated on 1 mol of d-norgestrel,in acetic acid containing not more than 50 mass percent of water, at15-50° C. for 15-45, min and after that the obtained reaction mixturecontaining the isomeric mixture of norelgestromin

-   -   1) is diluted with about a 10-fold volume of water and the        precipitated isomeric mixture is isolated to give an E/Z mixture        of isomers in a ratio of about 56:44-64:36, or    -   2) after addition of about 10-25 volume percent of water it is        stirred at 10-30° C. for 24-72 h, water is added to the reaction        mixture and the precipitated product is isolated to give the        (3E)-oxime isomer of Formula I, or    -   3) after addition of about 10-fold volume of water the        precipitated isomeric mixture is isolated and stirred in        dichloromethane, the insoluble (3E)-oxime isomer of Formula I is        filtered off, the filtrate is purified by column chromatography        using silica gel as adsorbent and a mixture of apolar-polar        solvents as eluent to give the (3Z)-oxime of Formula II, or

b) stirring a mixture of E/Z isomers of norelgestromin of any ratio

-   -   1) with hydroxylammonium acetate, or with a hydroxylammonium        salt and not more than one equivalent of alkali metal acetate,        in acetic acid containing not more than 50 mass percent of        water, at 15-30° C. for 24-72 hours and, in certain embodiments        after addition of additional water, isolating the product to        give the (3E)-oxime isomer of the Formula I, or    -   2) in dichloromethane, filtering off the insoluble (3E)-oxime        isomer of Formula I, purifying the filtrate by column        chromatography using silica gel as adsorbent and a mixture of        apolar-polar solvents as eluent to give the (3Z)-oxime of        Formula II, or

c) hydrolyzing the acetate group at position 17 of the 3E- or 3Z-isomerof norgestimate in alcoholic solution with an equivalent of alkali metalhydroxide at 5-30° C. to provide the obtained product, of the sameconfiguration as the starting material and isolating it to give the(3E)-oxime isomer of the Formula I or the (3Z)-oxime isomer of FormulaII;

and optionally purifying the isomers of Formula I and II obtainedaccording to processes a)-c) by crystallization.

In certain embodiments, the E or Z oxime isomer of norelgestromin isprepared having isomeric purity of at least 70%. In other embodiments,the E or Z oxime isomer of norelgestromin is prepared having isomericpurity of at least 80%. Other suitable levels of purity that can beobtained according to the present invention include but are not limitedto at least about 75%, 85%, 90%, 95%, 96%, 97%, 98%, and 99%.

Another aspect of the present invention relates to a process forpreparing E or Z oxime isomers of norelgestromin on a large scale. Anadvantage of the process described herein is that multigram quantitiesthe individual oxime isomers can be prepared in a safe and economicalfashion. The process of the invention can be readily adapted forindustrial synthesis of norelgestromin oxime isomers for use inmass-produced pharmaceutical compositions. For example, in oneembodiment, the yield of the process is at least about 10 grams, about20 grams, about 30 grams, or about 40 grams. In a preferred embodiment,the process further comprises recrystallizing the norelgestromin. Theyield refers to the amount of product obtained from a single batch. Inother embodiments, the yield of the process is from about 2 grams toabout 50 grams.

In another embodiment, the processes described herein can be used inconjunction with, as a part of, or in addition to, in whole or in part,the process described in copending application Ser. No. 10/879,708(Attorney Docket No. 2124.0040000) titled “Process for the synthesis ofhigh purityd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-oxime,”filed Jun. 30, 2004, which is incoporated herein by reference in itsentirety. For example, a process described therein for preparing a highpurity norelgrestromin can be used in conjunction with the methoddescribed herein for preparing a substantially pure E- or Z-oxime isomerof norelgestromin.

Pure Isomers

In a further embodiment, the present invention is directed to theisolated, substantially pure compounds of Formula I and II. Prior to thepresent invention, the characteristic physical properties of thesecompounds in pure form had not been characterized. Nor had theirstructures been unambiguously proven.

Furthermore, the present invention is directed to substantially pure,pharmaceutically acceptable amounts of E- and Z-isomers ofnorelgestromin. For example, in one embodiment, the present invention isdirected to substantially pure, pharmaceutically acceptable E- andZ-isomers of norelgestromin in an amount of at least 1 gram. Othersuitable amounts include 5, 10, 15, 20, 30, 40, and 50 grams.

Compositions

An additional aspect of the present invention is directed to acomposition comprising a substantially pure oxime isomer ofnorelgestromin. A composition according to the present inventionincludes a pharmaceutical composition comprising a substantially pureoxime isomer of norelgestromin and one or more pharmaceuticallyacceptable excipients. Pharmaceutical compositions of the presentinvention may be formulated, as is well known in the prior art, such asby reference to known compilations as Remington's PharmaceuticalSciences, Mack Publishing Co., Easton, Pa., USA.

In one embodiment, the invention is directed to a pharmaceuticalcomposition comprising substantially pure Z-norelgestromin and apharmaceutically acceptable carrier and/or excipient. In anotherembodiment, the pharmaceutical composition comprises substantially pureE-norelgestromin and a pharmaceutically acceptable carrier and/orexcipient. The amount of norelgestromin present in the composition canvary but is generally an amount effective to treat a condition asdescribed herein or known in the art. Other dosage amounts are describedherein.

The pharmaceutical compositions of the invention can be administered toany animal that can experience the beneficial effects of the compoundsof the invention. Foremost among such animals are humans, although theinvention is not intended to be so limited. Preferably, the compositionof the present invention is administered to a woman. Other animalsinclude bovines, canines, equines, and felines.

The pharmaceutical compositions of the present invention can beadministered by any means that achieve their intended purpose. Forexample, administration can be by subcutaneous, intravenous,intramuscular, intraperitoneal, buccal, or ocular routes, rectally,parenterally, intrasystemically, intravaginally, topically (as bypowders, ointments, drops or transdermal patch), or as an oral or nasalspray. The dosage administered may be dependent upon the age, health,and weight of the recipient, the kind of concurrent treatment, if any,the frequency of treatment, and the nature of the effect desired.

The pharmaceutical compositions of the present invention can preferablybe tablets, dragées, or transdermal patches. The tablets can contain, inaddition to the active ingredients, the usual carriers, excipients,diluents, stabilizers, flavoring or aromatizers, as well as formulationpromoting or formulation-providing additives. The formulation of tabletscan be carried out by methods conventionally used in practice. Thepreparation of dragées can be carried out, for example, by coating thedragées cores, prepared similarly to tablets, according to the usualmethods.

In one embodiment, the pharmaceutical composition of the presentinvention is a tablet comprising an amount of substantially pure E- orZ-norelgestromin effective to provide birth control or contraception.

In another embodiment, the dosage form is a tablet comprisingsubstantially pure Z-norelgestromin, for example about 0.1 to about 0.5mg, preferably about 0.25 mg, and ethinyl estradiol, for example about10 to about 50 μg. preferably about 35 μg. The tablet further comprisessuitable excipients, such as lactose, microcrystalline cellulose,colloid silicon dioxide (AEROSIL® (Evonik Degussa GmbH Ltd., Hanau,Del.)), and magnesium stearate.

In another embodiment, the tablet is formed by spray-drying a solutionof substantially pure Z-norelgestromin and ethinyl estradiol in solvent,such as ethanol, on a homogeneous mixture of lactose and cornstarch. Thesolvent is removed from the mixture by fluidization drying. The obtainedpowder mixture containing the active ingredients is granulated accordingto known methods and formed into tablets. Other suitable excipientsinclude polyvinylpyrrolidone (PVP), colloid silicon dioxide, andmagnesium stearate.

In another embodiment, the tablet comprises the substantially pureZ-isomer of norelgestromin, for example about 250 μg; ethinyl estradiol,for example about 35 μg; polyvinylpyrrolidone, for example about 2 mg;lactose, for example about 75 mg; cornstarch, for example about 20.5 mg;colloid silicon dioxide, for example about 1 mg; and magnesium stearate,for example about 0.5 mg.

In another embodiment, the pharmaceutical composition is a transdermalpatch comprising a substantially pure oxime isomer of norelgestromin.The patches can preferably be matrix-type transdermal patches consistingof 3 layers. Their external layer is a membrane, which is impermeablefor the active ingredients and other components of the matrix,consisting of PVC, polyethylene, polypropylene or polyurethane film. Thematrix containing the active ingredients is disposed on this externallayer. The matrix contains pressure sensitive adhesive component, whichcan be polyacrylate, polydimethylsiloxane or polyisobutylene. One ofthese adhesives is mixed with the active ingredients and thepolyvinylpyrrolidone auxiliary material, which inhibits crystallization.Auxiliaries (enhancers), which promote the absorption of steroidsthrough the skin, are preferably dispersed in the matrix as well. Thesecomponents can be for example esters of aliphatic alcohols, such aslauryl lactate, oleic acid, etc. The so obtained dispersion is disposedon the external layer of the patch and dried.

The matrix of the patch is covered by the third layer of the plaster,the protective layer, which can be for example a polyethyleneterephthalate film. The protective layer should be removed before theapplication of the patch to the skin.

In other embodiments, the transdermal matrix comprises one or morepermeation enhancers to increase the permeability of the norlegestrominand the optional estrogen through the skin. Examples of skin permeationenhancers that may be included in the matrix are described in U.S. Pat.Nos. 5,059,426, 4,973,468, 4,906,463 and 4,906,169, and include, but arenot limited to, lactate esters of C₁₂ to C₁₈ aliphatic alcohols, lauryllactate, oleic acid, or polyethylene glycol monolaurate. The amount ofpermeation enhancer included in the matrix depends upon the particularenhancer(s) used. In most instances, then enhancer constitutes about 1to about 20% by weight of the matrix.

Broadly, patches are devices that contain, at a minimum, a drugreservoir matrix for holding the drug and metering the drug depositionor delivery to the skin, a backing, and an adhesive layer for adheringthe device to the patient. The device may contain other layers such as adrug release rate controlling layer for modulating delivery rate, andthe like. The device may contain permeation enhancers to increase therate of penetration of drugs across the skin. Patches are well known andunderstood by persons skilled in the art. Patches are now employed inmarketed products for the administration of certain progestogen.Specific patches and even their application to steroids of the typedescribed herein are described in U.S. Pat. Nos. 5,474,783; 5,656,286;5,958,446; 6,024,976; 5,252,334; 5,006,342; and 4,906,463, each of whichis fully incorporated by reference herein. Other suitable transdermaldosage forms are disclosed in Published U.S. Patent Appln. Pub. No.20040043171, which is incorporated by reference in its entirety herein.

In certain embodiments, the patch of the invention has a basal surfacearea (i.e., the area in diffusional contact with the skin) between 10and 50 cm². Of course, various sizes and shapes of patches areunderstood to be within the scope of the present invention.

In one embodiment, the invention comprises a matrix type transdermalpatch of 3 layers containing 6.0 mg of substantially pure E-isomer ofnorelgestromin and 0.75 mg of ethinyl estradiol. For every patch unit,the composition comprises 6.0 mg substantially pure of E-isomer ofnorelgestromin, 0.75 mg of ethinyl estradiol, 25 mg ofpolyvinylpyrrolidone, 20 mg of lauryl lactate, and 248 mg ofpolylsobutylene.

In another embodiment, the matrix type transdermal patch of 3 layerscontains about 6.0 mg of substantially pure E-isomer of norelgestrominand about 0.75 mg of ethinyl estradiol. In another embodiment, thecomposition comprises 261 mg of polydimethylsiloxane and 17 mg ofpolyvinylpyrrolidone, 15 mg of methyl laureate, 6.0 mg of substantiallypure E-isomer of norelgestromin, and 0.75 mg of ethinyl estradiol.

In one embodiment, the dosage form, preferably the transdermal form,comprises an amount of active ingredients such that about 150 μg toabout 350 μg, preferably 175 μg to about 350 μg, of substantially pureE-norelegestromin, and about 5 μg to about 45 μg, preferably about 10 toabout 35 μg, more preferably about 20 μg of ethinyl estradiol aredelivered per day.

In one embodiment, the dosage form, preferably the transdermal form,comprises an amount of active ingredients such that about 150 μg toabout 350 μg, preferably 175 μg to about 350 μg, of substantially pureZ-norelegestromin, and about 5 μg to about 45 μg, preferably about 10 toabout 35 μg, more preferably about 20 μg of ethinyl estradiol aredelivered per day.

In another embodiment, the invention is directed to a transdermal patchfor providing hormone replacement therapy in a woman comprising: a) abacking layer; and b) a non-acrylate containing matrix layer underlyingthe backing layer, the matrix layer comprising a mixture ofsubstantially pure E-norelgestromin, an estrogen selected from the groupconsisting of ethinyl estradiol and 17-β-estradiol, lauryl lactate, anda pressure sensitive adhesive consisting essentially of polyisobutyleneand an aliphatic tackifier, and being adapted to be in diffusionalcommunication with the skin of a woman and to co-administer atherapeutic amount of said substantially pure E-norelgestromin and saidestrogen to said skin.

In another embodiment, the invention is directed to a transdermal patchfor providing hormone replacement therapy in a woman comprising: a) abacking layer; and b) a non-acrylate containing matrix layer underlyingthe backing layer, the matrix layer comprising a mixture ofsubstantially pure Z-norelgestromin, an estrogen selected from the groupconsisting of ethinyl estradiol and 17-β-estradiol, lauryl lactate, anda pressure sensitive adhesive consisting essentially of polyisobutyleneand an aliphatic tackifier, and being adapted to be in diffusionalcommunication with the skin of a woman and to co-administer atherapeutic amount of said substantially pure Z-norelgestromin and saidestrogen to said skin.

Other suitable transdermal dosage forms include those described in U.S.Pat. Nos. 5,876,746; 5,972,377; and 6,071,531, each of which is fullyincorporated by reference herein. The dosage forms disclosed in thesepatents can be used in accordance with the present invention byreplacing the 17-deacetylnorgestimate with the substantially pure E- orZ-norelgestromin of the present invention.

In addition to the pharmacologically active compounds, the newpharmaceutical preparations can contain suitable pharmaceuticallyacceptable carriers comprising excipients and auxiliaries thatfacilitate processing of the active compounds into preparations that canbe used pharmaceutically.

The pharmaceutical preparations of the present invention aremanufactured in a manner that is within the skill of the artisan, forexample, by means of conventional mixing, granulating, dragée-making,dissolving, or lyophilizing processes. Thus, pharmaceutical preparationsfor oral use can be obtained by combining the active compounds withsolid excipients, optionally grinding the resulting mixture andprocessing the mixture of granules, after adding suitable auxiliaries,if desired or necessary, to obtain tablets or dragee cores.

Pharmaceutical excipients are well known in the art. Suitable excipientsinclude fillers such as saccharides, for example, lactose or sucrose,mannitol or sorbitol, cellulose preparations and/or calcium phosphates,for example, tricalcium phosphate or calcium hydrogen phosphate, as wellas binders, such as, starch paste, using, for example, maize starch,wheat starch, rice starch, potato starch, gelatin, tragacanth, methylcellulose, hydroxypropylmethylcellulose, sodium carboxymethylcellulose,and/or polyvinyl pyrrolidone. If desired, disintegrating agents can beadded, such as, the above-mentioned starches and alsocarboxymethyl-starch, cross-linked polyvinyl pyrrolidone, agar, oralginic acid or a salt thereof, such as, sodium alginate. Auxiliariesare, for example, flow-regulating agents and lubricants, for example,silica, talc, stearic acid or salts thereof, such as, magnesium stearateor calcium stearate, and/or polyethylene glycol. Dragee cores areprovided with suitable coatings that, if desired, are resistant togastric juices. For this purpose, concentrated saccharide solutions canbe used, which may optionally contain gum arabic, talc, polyvinylpyrrolidone, polyethylene glycol, and/or titanium dioxide, lacquersolutions and suitable organic solvents or solvent mixtures. In order toproduce coatings resistant to gastric juices, solutions of suitablecellulose preparations, such as, acetylcellulose phthalate orhydroxypropylmethyl-cellulose phthalate, are used. Dye stuffs orpigments can be added to the tablets or dragee coatings, for example,for identification or in order to characterize combinations of activecompound doses.

In another embodiment, the pharmaceutical composition of the presentinvention is a vaginal ring. Vaginal rings are generally devices havingan elastomeric portion or body into which the active steroid isdispersed and which acts as a reservoir and meter for the diffusion ofactive to the lining of the vagina. The ring may be composed entirely ofelastomer with steroid homogenously dispersed throughout as described inU.S. Pat. No. 3,545,397. The ring may have an inert inner coresurrounded by an active containing elastomeric layer as described inU.S. Pat. No. 4,012,496. The ring may have an elastomeric activecontaining inner core surrounded by a thin elastomeric layer initiallycontaining no active. The ring may have an inert core, surrounded by anactive containing elastomeric layer and further surrounded by anelastomeric outer layer of variable thickness initially containing noactive as described in U.S. Pat. No. 4,292,965. The elastomer, thelayered design of the ring, its surface area, the concentration ofactive, the nature of the active, etc., all combine to determine therelease rate of active. Rings are well known and understood by personsskilled in the art. Rings are now employed in marketed products for theadministration of certain steroids. Other suitable rings include thosedescribed in U.S. Pat. Nos. 4,871,543 and 5,188,835, each of which isfully incorporated by reference herein.

Other pharmaceutical preparations which can be used orally includepush-fit capsules made of gelatin, as well as soft, sealed capsules madeof gelatin and a plasticizer, such as, glycerol or sorbitol. Thepush-fit capsules can contain the active compounds in the form ofgranules that may be mixed with fillers such as lactose, binders such asstarches, and/or lubricants such as talc or magnesium stearate and,optionally, stabilizers. In soft capsules, the active compounds arepreferably dissolved or suspended in suitable liquids, such as, fattyoils or liquid paraffin. In addition, stabilizers may be added.

Suitable formulations for parenteral administration include aqueoussolutions of the active compounds in water-soluble form, for example,water-soluble salts, alkaline solutions, and cyclodextrin inclusioncomplexes.

In other embodiments, the compounds of the invention are administeredparenterally as an injectable dosage form in a physiologicallyacceptable diluent such as sterile liquids or mixtures thereof,including water, saline, aqueous dextrose and other pharmaceuticallyacceptable sugar solutions, alcohols such as ethanol, isopropanol, orhexadecyl alcohol, glycols such as propylene glycol or polyethyleneglycol, glycerol ketals such as 2,2-dimethyl-1,3-dioxolane-4-methanol,ethers such as poly(ethyleneglycol)400, a pharmaceutically acceptableoil, fatty acid, fatty acid ester or glyceride, or an acetylated fattyacid glyceride with or without the addition of a pharmaceuticallyacceptable surfactant, such as a soap or detergent, suspending agentsuch as pectin, carbomers, methylcellulose,hydroxypropylmethylcellulose, or carboxymethylcellulose, an emulsifyingagent or pharmaceutical adjuvants. In all cases, the form must besterile and must be fluid to provide easy syringability.

Pharmaceutically acceptable oils which are useful in the formulationherein include those of petroleum, animal, vegetable or syntheticorigin, including peanut oil, soybean oil, sesame oil, cottonseed oil,olive oil, sunflower oil, petrolatum, and mineral oil. Fatty acids whichmay be used include oleic acid, stearic acid, and isostearic acid, whilethe fatty acid esters useful herein may include ethyl oleate andisopropyl myristate. Suitable soaps include fatty acid alkali metal,ammonium, and triethanolamine salts.

In addition, suspensions of the active compounds as appropriate oilyinjection suspensions can be administered. Suitable lipophilic solventsor vehicles include fatty oils, for example, sesame oil, or syntheticfatty acid esters, for example, ethyl oleate or triglycerides orpolyethylene glycol-400. Aqueous injection suspensions can containsubstances that increase the viscosity of the suspension, for example,sodium carboxymethyl cellulose, sorbitol, and/or dextran. Optionally,the suspension may also contain stabilizers.

Liquid dosage forms for oral administration include pharmaceuticallyacceptable emulsions, solutions, suspensions, syrups, and elixirs. Inaddition to the active compounds, the liquid dosage forms may containinert diluents commonly used in the art such as, for example, water orother solvents, solubilizing agents and emulsifiers such as ethylalcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzylalcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol,dimethyl formamide, oils (in particular, cottonseed, groundnut, corn,germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfurylalcohol, polyethylene glycols and fatty acid esters of sorbitan, andmixtures thereof.

Suspensions, in addition to the active compounds, may contain suspendingagents as, for example, ethoxylated isostearyl alcohols, polyoxyethylenesorbitol and sorbitan esters, microcrystalline cellulose, aluminummetahydroxide, bentonite, agar-agar, and tragacanth, and mixturesthereof.

Topical administration includes administration to the skin or mucosa,including surfaces of the lung and eye. Compositions for topicaladministration, including those for inhalation, may be prepared as a drypowder which may be pressurized or non- pressurized.

Compositions for vaginal administration are in one embodimentsuppositories which can be prepared by mixing the compounds of thepresent invention with suitable non-irritating excipients or carrierssuch as cocoa butter, polyethylene glycol or a suppository wax which aresolid at room temperature but liquid at body temperature and thereforemelt in the rectum or vaginal cavity and release the drugs.

In other embodiments, the compositions of the present invention can alsobe administered in the form of liposomes. As is known in the art,liposomes are generally derived from phospholipids or other lipidsubstances. Liposomes are formed by mono- or multi-lamellar hydratedliquid crystals that are dispersed in an aqueous medium. Any non-toxic,physiologically acceptable and metabolizable lipid capable of formingliposomes can be used.

Method of Treatment

In a further aspect of the invention, the compounds and compositionsdescribed herein are used to treat one or more ailments, conditions,diseases, or physiological states. The present invention comprisesadministering to a subject in need an effective amount of substantiallypure E- or Z-norelgestromin.

In one embodiment, the norelgestromin is administered via a transdermalpatch. The transdermal patch of the invention can provide contraceptionfor females, preferably women. The patch is also suitable for hormonereplacement therapy.

In certain embodiments, the patch delivers substantially pure E- orZ-norelgestromin and, optionally an estrogen, to the skin continuouslyfor an extended time period, for example 1-7 days and preferably for 7days.

In one embodiment, the effective dose of substantially pure E- orZ-norelgestromin for inhibiting ovulation is normally in the range ofabout 150 to about 350 μg/day, preferably from about 175 to about 300μg/day, and more preferably from about 175 to about 250 μg/day. Theeffective dose of estrogen for inhibiting ovulation depends on theparticular estrogen being co-administered. For instance, when theestrogen is ethinyl estradiol, the dose is normally at least 10 μg/day,preferably from about 10 to 35 μg/day, and most preferably approximately20 μg/day. In other embodiments, the typical doses are from about 20μg/day to about 200 μg/day, and preferably from about 30 μg/day to 150μg/day of ethinyl estradiol.

When the patches are worn for contraception, a patch is typically placedon the skin on the fifth day of the menstrual cycle, and replaced asneeded until 21 days of wearing have elapsed. For instance, in the caseof a 7-day patch, three patches are generally required to deliver thedrug(s) for the 21-day period. If desired, a placebo patch may be wornthereafter until the fifth day of the succeeding menstrual cycle. Thisregimen is repeated for each menstrual cycle.

In certain embodiments, an effective amount administered is from about150 to about 350 μg/day and preferably from about 175 to about 300μg/day of substantially pure E- or Z-norelgestromin. In one aspect, thesubstantially pure E- or Z-norelgestromin is co-administered with anovulation inhibiting amount of an estrogen, such as ethinyl estradiol.In other embodiments, an effective amount is from about 150 to about 350μg/day and preferably from about 175 to 300 μg/day of substantially pureE- or Z-norelgestromin and from 10 to 35 μg/day of ethinyl estradiol.

In one embodiment, the composition of the present invention isintravaginally administered, by use of a ring. Broadly, rings aredevices having an elastomeric portion or body into which the activesteroid is dispersed and which acts as a reservoir and meter for thediffusion of active to the lining of the vagina.

In one embodiment, the contraceptive regimen according to the presentinvention is a progestin-only contraceptive regimen in which thesubstantially pure E- or Z-oxime isomer of norelgestromin iscontinuously administered in a sufficient dose to have a contraceptiveeffect, and the regimen is administered cycle after cycle to amenstruating female to achieve a long term contraceptive effect. In suchregimens, no estrogen is administered, and there is no period of timewithout hormone administration to allow for menstruation. Menstruatingfemale is intended to refer to fertile women of child-bearing age. Themethod of administration might be transdermal, vaginal, or oral. Whereadministration is transdermal, a suitable patch is continuously wornwith replacement as required. Where administration is vaginal, asuitable vaginal device, such as a ring, is continuously inserted withreplacement as required. Where administration is oral, daily oral dosageunits are administered.

In certain embodiments, the cycle of administration usually lasts 28days or more, but it may be longer, for example up to 60 and even 90days, or shorter down to 21 days. The cycle optionally includes aregimen in which there is a day to day or week to week variation in thedose of norelegestromin administered according to a set pattern. In sucha case, the regimen, including variation of dose, is repeated in cyclefollowing cycle. Alternatively, the cycle may also be a regimen in whichthere is no variation in the dose of the active administered. In such acase, the cycle is a convention representing a convenient unit ofadministration or sale. In either case, a contraceptive productutilizing the contraceptive regimen in question is prescribed, sold, andadministered in units of cycles. The contraceptive product based on acycle might be 1 to 10 vaginal rings that are inserted and then replacedevery 7, 14, or 21 days according to their design. The contraceptiveproduct based on a cycle might be 2 to 10 transdermal patches that areattached and then replaced every 7, 10, or 14 days according to theirdesign. The contraceptive product based on a cycle might be 21, 28, 56,or more tablets that are orally administered daily.

In the case of a daily oral tablet, there is administered in certainembodiments a preferred dose of substantially pure E- orZ-norelgestromin between about 30 μg to about 500 μg and more preferablybetween about 150 μg to about 300 μg. Specific daily oral tabletscontain, for example, 100, 125, 180, 215, or 250 μg of substantiallypure E- or Z-norelgestromin. In the case of a vaginal ring, a certainembodiment of a ring delivers to systemic circulation a daily dose ofsubstantially pure E- or Z-norelgestromin between about 20 μg to about300 μg and more preferably between about 90 μg to about 200 μg. Aspecific vaginal ring might be inserted for one week and deliver tosystemic circulation in that period of time an average daily dose of 60,75, 100, 125 or 150 μg of substantially pure E- or Z-norelgestromin. Inthe case of a transdermal patch, a preferred patch delivers to systemiccirculation a daily dose of substantially pure E- or Z-norelgestrominbetween about 20 μg to about 300 μg and more preferably between about 90μg to about 200 μg. A specific patch might be worn for one week anddeliver to systemic circulation in that period of time an average dailydose of 60, 75, 100, 125, or 150 μg of substantially pure E- orZ-norelgestromin.

Other suitable regimens are disclosed in U.S. Published PatentApplications Pub.

Nos. 20030229057; 20030225048; 20030225047; and 20030219471, each ofwhich is fully incorporated by reference herein, and can be adapted todeliver the substantially pure E- or Z-norelgestromin

In one embodiment, the substantially pure E- or Z-norelgestromin isadministered in an amount effective to produce a contraceptive effect.According to another embodiment of the present invention, thesubstantially pure E- or Z-norelgestromin is administered in an amountwhich is an effective breast protective amount. For example, sufficientsubstantially pure E- or Z-norelgestromin may be administered such thatit is at least equivalent in both contraceptive and breast protectingeffect to about 0.030 mg to about 0.750 mg of orally administerednorgestimate. In another example, there is administered sufficientactive compound to provide for, during a substantial portion of eachday, a substantial suppression of sulfatase activity, for example, of50% or greater and preferably of 67% or greater and most preferably of75% or greater. A substantial portion of a day is intended to mean aperiod of at least 4 hours, but within the invention might mean a periodof at least 8 hours or 12 hours or even 24 hours.

In another embodiment, the invention provides a method of treating afemale in need of hormone replacement therapy comprising transdermallyadministering to said female a pharmaceutical patch regimen seriesconsisting essentially of a series of transdermal patches arranged inalternating phases of dominant hormone activity of from about one day toabout four days, said phases being selected from estrogen dominantactivity phases and progestin dominant activity phases. Each of thesephases can comprise at least one patch which is applied and removed inaccordance with the particular dominant phase activity, wherein theestrogen dominant activity phase contains an amount of a substanceexhibiting estrogen activity sufficient to promote the development ofprogestin receptors in the endometrium of said female, or an amount of asubstance exhibiting estrogen activity sufficient to promote thedevelopment of progestin receptors in the endometrium of said female andan amount of a substance exhibiting progestin activity; and wherein theprogestin dominant activity phases contain an amount of a substanceexhibiting estrogen activity and an amount of substantially pure E- orZ-norelgestromin sufficient to antagonize the effect of estrogen on theendometrium of said female. The estrogen and progestin are selected fromtransdermally administrable hormones. Such a general method is describedin further detail in U.S. Pat. No. 5,422,119, which is hereby fullyincorporated by reference herein.

The present invention also provides a method of hormone replacementtherapy. The substantially pure E- or Z-norelgestromin can be used in asuitable hormone replacement therapy regimen, either alone or incombination with other hormones. For example, in one embodiment, themethod provides from about 150 to about 350 μg/day, and preferably fromabout 175 to about 300 μg/day substantially pure E- or Z-norelgestrominco-administered with from about 5 to about 45 μg/day and preferably fromabout 10 to about 35 μg/day of an ethinyl estradiol. In an alternativeembodiment, the method provides from about 200 to about 350 μg/day, andpreferably from about 175 to about 300 μg/day substantially pure E- orZ-norelgestromin co-administered with from about 20 to about 175 μg/dayand preferably from about 30 to about 150 μg/day of 17-p-estradiol. Inother embodiments, the method of providing hormone replacement therapyis carried out by administering the compositions via a transdermal patchapplied to the skin for seven days.

Definitions

As used herein, the term “isomer of norelgestromin” refers to one of theoxime isomers of norelgestromin, i.e.,d-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oximeord-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oxime,as shown in Formulas I and II respectively.

As used herein, the term “E-norelgestromin” refers tod-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oximeas shown in Formula I. Other names synonymous with this term include“the E-isomer of norelgestromin,” “the E-oxime isomer ofnorelgestromin,” and variants thereof.

As used herein, the term “Z-norelgestromin” refers tod-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oximeas shown in Formula II. Other names synonymous with this term include“the Z-isomer of norelgestromin,” “the Z-oxime isomer ofnorelgestromin,” and variants thereof.

The term “substantially pure,” as used herein, refers to a compoundbeing at least about 90% isomerically pure with respect to the oximeisomers. For example, substantially pure Z-norelgestromin contains nomore than about 10% E-norelgestromin isomer. Likewise, for example,substantially pure E-norelgestromin contains no more than about 10%Z-norelgestromin isomer. In other embodiments, the E-norelgestromin orZ-norelgestromin isomer contains no more than 5%, 2%, or 1% of theZ-norelgestromin or E-norelgestromin isomer, respectively.

The invention is illustrated by the following examples, which are notmeant to limit the scope of the invention.

EXAMPLE 1d-(17α)-13-Ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(E/Z)-oxime

34.7 g (0.5 mol) of hydroxylammonium hydrochloride and 34 g (0.41 mol)of sodium acetate are suspended in 500 mL of glacial acetic acid, andafter stirring for 1 hour 31.2 g (0.1 mol) of d-norgestrel is addedunder nitrogen. The heterogeneous reaction mixture is stirred until thereaction is complete and then poured into 3000 mL of water. Theprecipitated product is filtered off, washed successively with water, 5%aqueous ammonium hydroxide solution, water until neutral then driedbelow 60° C. under vacuum.

The obtained crude product is dissolved in 320 mL of ethanol, anddecolorized with charcoal. After filtering the charcoal, the solution isconcentrated to a volume of 10% of the original. The residue is cooledto 0° C. and filtered after 5 h. The solid material is washed withethanol and dried to yield 29.4 g (90%) of the title compound. Mp.:110-130° C. (a mixture of oxime isomers). The ratio of the oximeisomers: E-oxime=58%; Z-oxime=42%.

EXAMPLE 2d-(17α)-13-Ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oxime

Under nitrogen, to a vigorously stirred suspension of 2.5 g (0.035 mol)of hydroxylammonium hydrochloride, 2 g (0.024 mol) of sodium acetate and55 mL of 70% aqueous acetic acid, 5 g (0.016 mol) of d-norgestrel isadded and stirring is continued for 50 h. The reaction mixture is pouredinto 500 mL of water. The precipitated product is filtered off, washedsuccessively with water, 5% aqueous ammonium hydroxide solution, andwater until neutral, and then dried below 60° C. The obtained crudeproduct (the ratio of the oxime isomers: E-oxime=94.5%; Z-oxime=5.5%) isrecrystallized from dichloromethane to yield 4.65 g (88.7%) of the titlecompound, the pure E-isomer. Mp.: 198-200° C.

EXAMPLE 3d-(17α)-13-Ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oxime

5 g (0.07 mol) of hydroxylammonium hydrochloride and 5.8 g (0.07 mol) ofsodium acetate are suspended in 100 mL of glacial acetic acid. Thesuspension is stirred for 1 h, and the formed sodium chloride isfiltered off. Under nitrogen, 10 g (0.032 mol) of d-norgestrel is addedto the stirred filtrate and stirring is continued until the reaction iscomplete. Then 30 mL of water is added to the reaction mixture, andstirring is continued for a further 50 h. The reaction mixture is pouredinto 1000 mL of water. The precipitated product is filtered off, washedaccording to the method described in Example 2, and dried. The crudeproduct is recrystallized from acetonitrile to yield 9.1 g (86.8%) ofthe title compound, the pure E-isomer. Mp.: 198-200° C.

EXAMPLE 4d-(17α)-13-Ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oxime

Under nitrogen, to a vigorously stirred suspension of 10 g (0.027 mol)of d-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-3(E/Z)-oxime (ratio of isomers: E-oxime 58%, Z-oxime 42%) and 100 mL ofglacial acetic acid 2.5 g (0.035 mol) of hydroxylammonium hydrochlorideand 2.9 g (0.035 mol) of sodium acetate in 20 mL of water are added. Thereaction mixture is stirred for another 50 h and then poured into 1000mL of water. The reaction mixture was treated as described in Example 2to yield 9.6 g (96%) of the crude product. The obtained product (ratioof isomers: E-oxime 94%. Z-oxime 6%) is recrystallized from ethylacetate according to the method described in Example 2 to yield 9.1 g(91%) of the title compound, the pure E-isomer. Mp.: 197-199° C.

EXAMPLE 5d-(17α)-13-Ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oxime

A suspension of 43.8 g (0.53 mol) of sodium acetate, 50 g (0.72 mol) ofhydroxylammonium hydrochloride, and 100 mL of 90% aqueous acetic acid isvigorously stirred at room temperature for 1 h. The precipitated sodiumchloride is filtered off, 100 g (0.32 mol) of d-norgestrel is added tothe filtrate under nitrogen, and the resulting mixture is stirred for1.5 h. During this time, the temperature of the reaction is allowed torise to 45° C. The reaction mixture becomes homogeneous, which indicatesthat the reaction is complete. The reaction mixture is poured into 4000mL of water. The precipitated product is filtered off, washedsuccessively with water, 5% aqueous ammonium hydroxide solution, andthen water until neutral, and then dried. The obtained 104 g isomericmixture of oximes (ratio of isomers: E-oxime 57.4%, Z-oxime 42.6%) isvigorously stirred with 20-fold volume of dichloromethane for 30 min.The insoluble material is filtered off and dried below 60° C. to yield45.6 g of product (ratio of isomers: E-oxime 94.4%, Z-oxime 4.6%.

The mother liquor obtained after isolating the above product isconcentrated to yield 58 g of a mixture of isomers (Z-oxime 65.5%,E-oxime 33.2%). The residue obtained is dissolved in 2300 mL (40-fold)of dichloromethane and kept at 0-5° C. for 5 h. The precipitatedcrystalline product is filtered off, washed with dichloromethane, anddried to yield 17.6 g of product (ratio of isomers: E-oxime 9%, Z-oxime91%).

The mother liquor obtained from the crystalliztion is also concentrated,and the residue (39 g) is purified by column chromatography using 700 gof silica gel as adsorbent and toluene followed by a more polar mixtureof toluene-acetone as eluent. The fractions containing the same isomerare concentrated to yield 3.7 g of E-oxime (isomer purity: 94%) and 25.2g of Z-oxime (isomer purity: 95%).

The corresponding crystals obtained by crystallization and by columnchromatography are combined and recrystallized first from 20-fold volumeof acetonitrile, and then from 23-fold volume of ethyl acetate to yield29 g of Z-oxime (purity: 99.3%) and 38.4 g of E-oxime (purity: 99.7%).Mp: Z-oxime: 206-207° C., mp.: E-oxime: 199-200° C.

Specific rotations: Z-oxime: [α]²⁰ _(D)=+106.4° (c=0.5, CHCl₃); E-oxime:[α]²⁰ _(D)=−1.6° (c=0.5, CHCl₃).

NMR data: Z-oxime: ¹H NMR (500 MHz, DMSO-d₆(TMS), δ(ppm)): 0.92 (3H, t,—CH₂—CH₃), 1.40 (2H, m, —CH₂—CH₃), 2,05 & 2.24 (2H, m & m, H-2), 3.28(1H, s, ≡CH), 5.23 (1H, s, 17-OH), 6.40 (1H, m, H-4), 10.12 (1H, s,═N—OH).

¹³C NMR (125 MHz, DMSO-d₆(TMS), δ (ppm)): 9.4 (—CH₂—CH₃), 18.3(—CH₂—CH₃), 26.9 (C-2), 79.6 (C-17). 89.1, (—C≡), 74.9 (≡CH), 111.6(C-4), 151.2 (C-3), 152.0 (C-5).

E-oxime: ¹H NMR (500 MHz, DMSO-d₆ (TMS), δ (ppm)): 0.92 (3H, t,—CH₂—CH₃), 1.40 (2H, m, —CH₂—CH₃), 187 & 2.87 (2H, m & m, H-2), 3.28(1H, s, ≡CH), 5.23 (1H, s, 17-OH), 5.78 (1H, m, H-4), 10.38 (1H, s,═N—OH).

¹³C NMR (125 MHz, DMSO-d₆ (TMS), δ (ppm)): 9.4 (—CH₂—CH₃) 18.3(—CH₂—CH₃) 20.6 (C-2) 79.6 (C-17), 89.1 (—C≡), 74.9 (≡CH), 118.6 (C-4),154.3 (C-3), 148.1 (C-5).

EXAMPLE 6d-(17α)-13-Ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oxime

Under nitrogen, to a vigorously stirred solution of 10 g (0.027 mol) ofd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oximeand 100 mL of 80% aqueous acetic acid (0.035 mol) of hydroxylammoniumhydrochloride and 2.9 g (0.035 mol) of sodium acetate are added. Thereaction mixture is stirred for about 50 h, and then purified asdescribed in Example 4 to yield 8.5 g (85%) of the title compound, thepure E-oxime. Mp: 196-198° C.

EXAMPLE 7d-(17α)-13-Ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oxime

Under nitrogen, to a vigorously stirred solution of 5 g (0.01 mol) ofd-(17α)-13-ethyl-17(acetyloxy)-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oximein 50 mL of methanol, 1.7 g (0.04 mol) of lithium hydroxide monohydrateis added at 0-5° C. and stirring is continued for another 2 h. After thereaction is complete (as checked by thin layer chromatography), thereaction mixture is poured into 500 mL of water and the pH of theobtained suspension is adjusted to 7.5-9 with acetic acid. Theprecipitated product is filtered off, washed with water until neutral,and then dried below 60° C. in vacuum. The obtained crude product (4.5g) is recrystallized from acetonitrile to yield 4 g (90.2%) ofd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oxime;mp: 203-204° C.

d-(17α)-13-Ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oximeis prepared according to the method described above from 5 g ofd-(17α)-13-ethyl-17-(acetyloxy)-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oxime.Yield: 4.1 g (92.45%); mp: 198-200° C.

EXAMPLE 8d-(17α)-13-Ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oxime

Under nitrogen, to a vigorously stirred suspension of 1.25 g (0.017 mol)of hydroxylammonium hydrochloride and 1.45 g (0.017 mol) of sodiumacetate in 60 mL of 50% aqueous acetic acid 2.5 g (0.008 mol) ofd-norgestrel is added. After the reaction is complete (checked by thinlayer chromatography), the reaction mixture is poured into 500 mL ofwater. The precipitated product is filtered off, washed successivelywith water, 5% aqueous ammonium hydroxide solution, and water untilneutral, and then dried below 60° C. The crude product is recrystallizedfrom dichloromethane to yield 2.27 g (86.7%) of the title compound. Mp.:198-200° C.

EXAMPLE 9d-(17α)-13-Ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-oxime(mixture of isomers)

To a vigorously stirred suspension of 5.8 g (0.07 mol) of sodium acetatein 80 mL of glacial acetic acid, 5 g (0.07 mol) of hydroxylammoniumhydrochloride in 22 mL of water is added. Then 10 g (0.032 mol) ofd-norgestrel is added to the reaction mixture under nitrogen andstirring is continued until the reaction is complete (as checked by thinlayer chromatography). The reaction mixture is poured into 800 mL ofwater. The precipitated product is filtered off, washed successivelywith water, 5% aqueous ammonium hydroxide solution, and water untilneutral, and then dried below 60° C. to yield 8.9 g (84.92%) of thetitle compound as a 55.8/44.2 mixture of E/Z-isomers. Mp.: 110-130° C.

EXAMPLE 10 Pharmaceutical Composition Containingd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oximeand Ethinyl Estradiol as Active Ingredients in Tablet Form

250 mg of Z-isomer of norelgestromin and 35 mg of ethinyl estradiol ismixed homogeneously with 75.715 g of lactose, 22.5 g of microcrystallinecellulose, 1 g of colloid silicon dioxide (AEROSIL® (Evonik Degussa GmbHLtd., Hanau, Del.)) and 500 mg of magnesium stearate. The obtainedpowder mixture is compressed into tablets of 100 mg without granulation.About 1000 tablets are obtained.

EXAMPLE 11 Pharmaceutical Composition Containingd-(17α)-13-ethyl-17-hydrox-y-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oximeand Ethinyl Estradiol as Active Ingredients in Tablet Form

250 mg of Z-isomer of norelgestromin and 35 mg of ethinyl estradiol aredissolved in 10 mL of ethanol and the so obtained mixture is sprayed ona homogeneous mixture of 75.715 g of lactose dried 20.5 g of cornstarch.Ethanol is removed from the mixture by fluidization drying. The obtainedpowder mixture containing the active ingredients is granulated with anaqueous solution of 2 g of polyvinylpyrrolidone (PVP) in fluidizationequipment, and then dried. 1 g of colloid silicon dioxide and 0.5 g ofmagnesium stearate are homogenized with the granulated material. Thegranulated material is compressed into tablets of 100 mg. About 1000tablets are obtained.

EXAMPLE 12 Pharmaceutical Composition Containingd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oximeand Ethinyl Estradiol as Active Ingredients in Tablet Form

250 mg of Z-isomer of norelgestromin, 35 mg of ethinyl estradiol and 2 gof polyvinylpyrrol idone (PVP) are dissolved in 10 mL of ethanol, andthe so obtained mixture is sprayed on a homogeneous mixture of 75.715 gof lactose and 20.5 g of cornstarch in a high shear mixer. The mixtureis granulated, and the ethanol is removed in a microwave vacuum drier. 1g of colloid silicon dioxide and 0.5 g of magnesium stearate arehomogenated to the granulated material. The granulated material iscompressed into tablets of 100 mg. About 1000 tablets are obtained.

EXAMPLE 13 Pharmaceutical Composition Containingd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oximeand Ethinyl Estradiol as Active Ingredients in Transdermal Patch Form

A one-piece, matrix-type transdermal patch of 3 layers containing 6.0 mgof E-isomer of norelgestromin and 0.75 mg of ethinyl estradiol isprepared as follows.

For every patch unit 6.0 mg of E-isomer of norelgestromin, 0.75 mg ofethinyl estradiol, 25 mg of polyvinylpyrrolidone, 20 mg of lauryllactate (absorption promoting agent) and 248 mg of polylsobutylene aredispersed in a 8:1:1 mixture of hexane/ethyl acetate/ethanol at roomtemperature for 45 min. The so obtained dispersion is poured onto theexternal membrane of the patch and dried at 70° C. for about 45 min. Aprotective membrane is layered on the surface of the dried matrix.

EXAMPLE 14 Pharmaceutical Composition Containingd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4ene-20-yn-3-one-(3E)-oximeand Ethinyl Estradiol as Active Ingredients in Transdermal Patch Form

A one-piece, matrix-type transdermal patch of 3 layers containing 6.0 mgof E-isomer of norelgestromin and 0.75 mg of ethinyl estradiol isprepared as follows.

For every patch unit, 261 mg of polydimethylsiloxane and 17 mg ofpolyvinylpyrrolidone is homogenated at room temperature. 15 mg of methyllaureate, 6.0 mg of E-isomer of norelgestromin and 0.75 mg of ethinylestradiol are added to the mixture, and it is dispersed with 350 mL ofethanol at room temperature for 45 min. The so obtained dispersion ispoured onto the external membrane of the patch and dried at 70° C. forabout 45 min. A protective membrane is layered on the surface of thedried matrix.

EXAMPLE 15 Determination of Physicochemical Parameters of Isomers

According to the relative orientation of the hydroxyl group of the oximegroup of norelgestromin, there are two geometric isomers of thecompound. These isomers can be separated by column chromatography. Asdetermined herein, the Z isomer is more polar than the E isomer. Forisomers that differ in polarity, absorption through the skin may alsodiffer. This issue is relevant to, e.g., the application of isomericmixtures of norelgestromin in transdermal patches. This issue wasinvestigated. The investigations included the physico-chemicalproperties of the pure isomers as well as their in vitro pharmacokineticstudy. During the physicochemical study, the water solubility of theindividual norelgestromin isomers was determined, as well as theirlipophilicity by traditional and isocratical HPLC.

Protocol for Solubility Measurement

The determination of equilibrium solubility of E and Z isomers ofnorelgestromin was carried out in distilled water. 20 mg ofnorelgestromin was added to 20 mL of distilled water at roomtemperature. The suspension was stirred continuously and samples werewithdrawn from time to time. The samples were filtered, and thenorelgestromin content of the filtrates was determined by aspectrophotometrical method measuring UV absorption. Thespectrophotometrical measurements were performed on a VARIAN Cary 3Espectrophotometer at room temperature.

Protocol for Lipophilicity Measurement

Lipophilicity was determined by an HPLC method. The HPLC measurementswere performed on a Thermo Separation Product (SpectraSystem P4000 andSpectraFOCUS Forward Optical Scanning Detector) HPLC instrument. Datawere analyzed by ChromQuest (ver. 2.51) software.

For reversed-phase HPLC measurements, a Nova-Pak C18 column was used(dimension of 4 μm×4.6 mm×250 mm: Waters, Ireland). Detection wasperformed at λ=280 nm and 25° C. The flow rate of the mobile phase was1.0 mL/min. HPLC gradient grade acetonitrile was used as organiccomponent (Merck KGaA., Darmstadt, Germany). The retention data of thetwo isomers were obtained by isocratical analysis of the mobile phasescontaining different amounts of acetonitrile. The void time (t₀) wasdetermined by injection of methanol.

Samples were dissolved in a 1:1 mixture of acetonitrile:water in aconcentration of 1 mg/4 mL. The log k′ values were calculated from themean retention time measured after two subsequent injections of 10 μLvolume (log k′=log((tR−t₀)/t₀)). The log k′ values were represented as afunction of the concentration of acetonitrile. The void time (t₀) wasfound to be 1.49 min in this experimental arrangement.

The chromatographical hydrophobicity index (CHI) is a measure of thelipophilic character of the compounds in the reversed phase HPLCmeasurements. By definition, the CHI parameter is that concentration ofacetonitrile of the mobile phase where log k′=0.

TABLE 1 Parameter E-isomer Z-isomer Water solubility 3.8 μg/mL 12.1μg/mL Polarity (k′, HPLC) 1.02 1.46 Polarity (CHI index, HPLC) 74 70

EXAMPLE 16 Determination of Metabolic and Distribution Parameters ofIsomers of Norelgestromin

The in vitro pharmacokinetic study included the metabolic stability, themetabolic clearance, and the Caco-2 permeability of the compounds.

Protocol for Assessment of Metabolic Stability and Clearance

The metabolic stability of norelgestromin E and Z isomers was examinedin human liver microsomes. The 2.5 mL incubation mixture contained 6 mMof Na-pyrophosphate, 5 mM of MgCl₂, 5 mM of glucose-6-phosphate, 1 U/mLof glucose 6-phosphate dehydrogenase, human liver microsomes (1 mg/mL)and 5 μM of norelgestromin E or Z isomers. The pH was adjusted with 100mM of Tris-HCl buffer to pH 7.4. The reaction was started by theaddition of 5 mM of NADPH. 0.5 mL samples were taken at 0.5 and 20minutes with immediate precipitation by 0.5 mL of ice-cold methanol. 1mL precipitated samples were centrifuged for 30 min at 1200 g, and 10 μLof supernatant was injected into the HPLC.

Analytical measurements were conducted using a Merck-Hitachi HPLCsystem, with UV monitoring at 244 nm. Unchanged material was measuredand intrinsic clearance (Cl_(int)) and metabolic bioavailability (F%)was calculated with the following equations:

dc/dt/c ₀ =Cl _(int), (mL/min×g protein),

where dc/dt is the concentration change in a given period of time and c₀is the initial concentration of the norelgestromin isomer (measured inthe 0 min sample). Additionally,

Cl _(int)×45=Cl _(int2) (mL/min×g liver) and

EH=Cl _(int2) /Cl _(int2) +HBF,

where EH is hepatic extraction and HBF is the hepatic blood flow.Finally the metabolic stability:

F%=(100−EH)×100

For statistical analysis, Student's t-test was used (Microsoft Excel).The results summarized in Table 2 are calculated as a mean of 3 parallelmeasurements.

Protocol for Caco-2 Permeability Measurement

Drug absorption studies were performed with Caco-2 human adenocarcinoma(epithelial) cell line monolayers as an in vitro model. Passive fluxcharacteristics of drugs across the Caco-2 monolayer have shown acorrelation with human oral bioavailability.

Caco-2 cells obtained from American Type Culture collection, Rockville,Md., (ATCC) were grown at 37° C. in an atmosphere of 5% CO₂ inDulbecco's modified eagle medium supplemented with 10% heat inactivatedfetal bovine serum (GIBCOBRL 11360-039) and antibiotics: penicillin 100U/mL, and streptomycin 100 μg/mL (GIBCOBRL 15140-031).

Confluent cell monolayers grown in an incubator (at 37° C. with 5%CO₂/95% O₂ and 95% humidity) were subcultured every seven days bytreatment with 0.25% trypsin containing 1 mM EDTA.

19-23-day-old confluent monolayers of fully differentiated Caco-2 cellswere used for transport studies after 6-10 passages.

EHS Cell Attachment Matrix (Promega G5971), Minimum Essential mediumEagle (MEM) with Earle salts, L-Glutamine (GIBCOBRL 41500-091) andTranswell Polycarbonate Membrane (Costar 3401) were used.

Coated Transwells with EHS Cell Attachment Matrix (Promega G5971) and200000-500000 Caco-2 cells are applied/inserted. Caco-2 monolayers weregrown on the luminal side/apical compartment of transwells.

The E- and Z-isomers of norelgestromin were assayed at 50 μMconcentration. [¹⁴C]-Mannit was used as paracellular marker (3.7×10⁴Bq/test chamber).

After removal of cell culture medium, three parallel Caco-2 cellmonolayers were preincubated for each test compound with prewarmed (37°C.) HBBS-TRIS (400 μL to the luminal side and 1.5 mL to the basolateralside/compartment) for 20 min at 37° C.

The medium was changed, followed by addition of 0.4 mL 50-100 gM workingconcentration of investigated and reference molecules to theluminal/apical compartment of inserts.

Measurement of absorption (luminal side to basolateral side) was made byobtaining samples from the luminal/apical (“donor”) compartment at zerotime point and from the basolateral (“receiver” side) at every 15 min(3×).

The concentrations of the isomers were determined by liquidchromatography with ultraviolet (HPLC/UV) analysis. Method: gradientelution at 35° C. Eluent A: methanol −0.05 M, ammoniumacetate=300-200+500 μL 10% acetic acid. Eluent B: methanol. Flow: 0.50mL/min. Detection: 240 nm. Column type: Merck Purospher C-18.

Dim.: 125-3 mm.+guard. Chrom Type: HPLC Channel:2. Peak quantitation:height; calculation method: EXT-STD.

The albuminal concentrations of the penetrated isomers are shown inTable 2.

TABLE 2 Parameter E-isomer Z-isomer Metabolic stability 86.7 ± 1.67 91.9± 1.52 Metabolic clearance 0.1815 ± 0.026  0.1042 ± 0.021  (mL/min gliver) Concentration on the 1.27 ± 0.56 1.98 ± 0.78 abluminal side (μMin the 30^(th) min)

As the above data show, the Z-isomer of norelgestromin is more solublein water than the E-isomer. In the case of the Z-isomer, the penetrationacross the epithelial cell layer is faster, the metabolic stability ishigher, and the clearance is lower than in the case of the E-isomer.These properties show that, after oral administration, the absorption ofthe Z-isomer is expected to be better than that of the E-isomer.Therefore, use of the Z-isomer in orally administered formulations (forexample in tablets) is more advantageous.

EXAMPLE 17

Siddiqui, et al., J. Pharm. Biopharm., 17:405 (1989), have shown bycarrying out experiments on isolated human skin preparations that thelipophilic steroids penetrate faster across the human epidermis than thepolar steroids, but the rate of clearance is about the same in bothcases. According to the experiments of solubility and polarity providedherein, the E-isomer of norelgestromin is significantly more lipophilicthan the Z-isomer. According to the experiments of Siddiqui andcoworkers, the penetration of the more lipophilic E-isomer is fasteracross the epidermis than that of the Z-isomer. Therefore theapplication of E-isomer in transdermal patches is more advantageous.

The beneficial effect of the increasing lipophilicity for thetransdermal absorption was proven by carrying out a structure-absorptionexperiment with six different steroids. In the following publications:Int. J. Pharm. 217:1 (2001), and J. Chromatography 49:631 (1993), it hasbeen shown that the chrormatographical hydrophobicity index (CHI)measured under isocratical conditions is a reliable descriptor oflipophilicity. The CHI values of the investigated steroids weredetermined according to these experiments (Table 3) and correlated withthe measured stratum corneum/water distribution coefficients.

TABLE 3 Steroid compound CHI Log Kp Hydrocortisone 33.8 −9.08 Estriol40.45 −7.95 Cortexolone 54.87 −7.68 Estradiol 65.19 −7.08 Testosterone75.87 −6.95 Pregnenolone 95.36 −6.38

The obtained good correlation (r²=0.88) shows that the steroid having ahigher CHI index, i.e., is more lipophilic, penetrates better across thestratum corneum. FIG. 1 shows the correlation between measured andpredicted log K_(p) data (95% confidence intervals are indicated bydashed lines) for other steroids. According to our measurements, the CHIindex of the E-isomer is higher than that of the Z-isomer. In apreferred embodiment, the substantially pure E-isomer of norelgestrominis formulated as a transdermal patch.

Having now fully described this invention, it will be understood bythose of ordinary skill in the art that the same can be performed withina wide and equivalent range of conditions, formulations and otherparameters without affecting the scope of the invention or anyembodiment thereof. All patents and publications cited herein are fullyincorporated by reference herein in their entirety.

1-20. (canceled)
 21. A process for preparing norelgestromin, comprisinghydrolyzing the acetate group at position 17 of the 3E- or 3Z-isomer ofnorgestimate in alcoholic solvent with an equivalent of alkali metalhydroxide.
 22. The process according to claim 21, further comprisingrecrystallizing the norelgestromin.
 23. The process according to claim21, wherein the norgestimate is substantially pure 3Z-norgestimate. 24.The process according to claim 21, wherein the norgestimate issubstantially pure 3E-norgestimate.
 25. The process according to claim21, wherein the hydrolysis is carried out at a temperature of about 5°C. to about 30° C.; the alkali metal is lithium hydroxide monohydrate;and the solvent is methanol.
 26. Isolated, substantially pured-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oximesuitable for use in a pharmaceutical composition.
 27. Isolated,substantially pured-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oximesuitable for use in a pharmaceutical composition.
 28. A pharmaceuticalcomposition comprising the substantially pured-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oximeof claim 26, and a pharmaceutically acceptable carrier.
 29. Thepharmaceutical composition according to claim 28, wherein saidcomposition contains less than 5% ofd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oxime.30. The pharmaceutical composition according to claim 28, wherein saidcomposition contains less than 2% ofd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oxime.31. The pharmaceutical composition according to claim 28, wherein saidcomposition contains less than 1% ofd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oxime.32. The pharmaceutical composition according to claim 28, wherein saidcarrier is selected from the group consisting of excipients, diluents,stabilizers, flavoring additives, aromatizing additives,formulation-promoting additives, formulation-providing additives, andcombinations thereof.
 33. The composition according to claim 28, whereinsaid composition is a patch.
 34. The composition according to claim 28,wherein said composition is an oral dosage form.
 35. A pharmaceuticalcomposition comprising the substantially pured-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-)3Z)-oximeof claim 27, and a pharmaceutically acceptable carrier.
 36. Thepharmaceutical composition according to claim 35, wherein saidcomposition contains less than 5% ofd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oxime.37. The pharmaceutical composition according to claim 35, wherein saidcomposition contains less than 2% ofd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oxime.38. The pharmaceutical composition according to claim 35, wherein saidcomposition contains less than 1% ofd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oxime.39. The pharmaceutical composition according to claim 35, wherein saidcarrier is selected from the group consisting of excipients, diluents,stabilizers, flavoring additives, aromatizing additives,formulation-promoting additives, formulation-providing additives, andcombinations thereof.
 40. The composition according to claim 35, whereinsaid composition is a patch.
 41. The composition according to claim 35,wherein said composition is an oral dosage form.
 42. A method ofeffecting contraception in a female, comprising administering apharmaceutical composition comprising a substantially pure oxime isomerof norelgestromin selected from:d-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3E)-oximeandd-(17α)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-ene-20-yn-3-one-(3Z)-oxime;and a pharmaceutically acceptable excipient or carrier, wherein saidoxime isomer is administered in an amount effective to effectcontraception.